'''
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with self work for additional information
 * regarding copyright ownership.  The ASF licenses self file
 * to you under the Apache License, Version 2.0 (the
 * "License") you may not use self file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http:#www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
'''
from base.graph.Node_Ext import Node_Ext

'''
 * Marker special nodes for datastructures.
 * The application is responsible for allocating unique strings.
'''
# 原本继承的是 Node_Ext<String>
class Node_Marker(Node_Ext):

    # param String str
    # result static Node
    def xlabel(self, str):
        return Node_Marker(str)
    

    def __init__(self, label):
        super().__init__(label)
    

    #@Override
    # param 
    # result boolean
    def isConcrete(self):
        return False
    

